Supplementary Financial Information (Schedule Of Operating Lease, Third Party Joint Project And Other Obligations) (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Supplementary Financial Information [Abstract]
Operating lease liabilities (Notes 1 and 7)	$ 135	$ 133
Investment tax credits	4	4
Customer deposits - noncurrent	66	30
Other	72	64
Total operating lease, third party joint project and other obligations	$ 277	$ 231

Amount of liabilities classified as other, due after one year or the normal operating cycle, if longer.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.24)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Name:	us-gaap_OtherLiabilitiesNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant